/Engine/Plugins/Runtime/MassGameplay/Source/MassSpawner/Public/MassEntityTemplateRegistry.h
Initializes and stores the EntityManager the templates will be associated with. Needs to be called before any template operations. Note that the function will only let users set the EntityManager once. Once it's set the subsequent calls will have no effect. If attempting to set a different EntityManaget an ensure will trigger.
void Initialize ( const [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FMassEntityManager](API\Plugins\MassEntity\FMassEntityManager) > & InEntityManager )